Improved countersink



nited Staten @anni 619mm.

ASA WHEELER, 0F BRATTLEBOROUGH, VERMONT, ASSIGNOR TO GEORGE B. WHEELER'OF SAME PLACE.

Letters Patent No. 101,796, dated Apr/il 12, 18,70.

IMPROVE!) COUNTERSINK.

' The Schedule referred to in these Letters Patent and making part of the same.

ATo all whomJ yit may concern.

panying drawings, forming part of this specification.

This invention relates to improvements in countersinks, and in the mode of making them.

Figure 1 represents an elevation of my improved eountersink.

Figure 2 represents a section on the line I :c of fig.

Similar letters of reference indicate corresponding parts.

The bit. is formed in the shape ofa hollow eccentric cone, with an angular slot at the line from the point to the base 'of the cone, where the sides of the parts with the' greater and lesser radiimeet, represented by a, forming the projecting cutting-lip b'.

The base of the bit is united to the handle d by a section representing about half or little more than halt' a cone, c, having its base connected to the inverted baseof the bit.

l his section may be divided, or have apart removed at its center, if preferred. The slot brming the lipis arranged opposite the opening e, formed by the removal of the part of the cone c, whereby the chips taken in through the slot in cutting are more readily' crowded out'or discharged than when the lips are arranged opposite the parts e, and clogging prevented.

Similar tools have been heretofore made by forging the bits out into their triangular shape from a rod of metal, and bending them up in'to the required form, and then suitably nishing them. This method is slow and expensive, and -I propose to make them by cast-ing, malleableizing, and steelifying them, the latter heilig accomplished .by the process ot' cementation or otherwise, as preferred.

When made by forging, as in the coinlnon way, the

. bits are connected to the shanks bya bent part there;

of, which does not have sntllcient stock to sustain the, resistance of the cutting, and is very liable to bendv and twist, whereas, when formed by casting, any required amount of stock may be placed at this point to make it perfectly rigid, especially when made broad and divided, so that the two parts assume the form of' braces.

Having thus described my invention,

I claiin as new and desire to Secure by Letters Patent- The eonntersink a b c d e formed of metal, east, malleablezed and steelitied, as and for the purpose specified. ASA lVHEELER. Witnesses:

`WILLIAM S. NEWTON, J Ennr Harina. 

